<template>
  <div>
    <ul>
      <li v-for="(val, index) in arr" :key="index">
        <!-- :value动态 -->
        <input type="checkbox" v-model="num" :value="val" />
        <span>{{ val }}</span>
      </li>
    </ul>
    <p>你选中的元素累加和为:{{ sum }}</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [9, 15, 19, 25, 29, 31, 48, 57, 62, 79, 87],
      num: [],
    };
  },
  computed: {
    sum() {
      return this.num.reduce((sum, obj) => (sum += obj), 0);
    },
  },
};
</script>

<style>
</style>